Microsoft confirmed Monday that Windows 8 users who upgrade the Calendar app will no longer be able to synchronize that schedule with the calendar included with Google Apps for Business, Academic or Government.

"Google's paying customers and those with business accounts will not be able to sync their calendars in the [Calendar] app update," a Microsoft spokeswoman said Monday.

Calendar was one of three "Modern" UI (user interface) apps that Microsoft just upgraded for Windows 8 and Windows RT. The same day, The Verge reported that the updated Calendar app would not sync with Google Calendar.

Microsoft's confirmation that Google Apps account owners would no longer be able to sync schedules with Windows 8's Calendar was counter to what Microsoft had said previously, and even continued to state today.

"If you've already connected your Google account to your PC using the Mail, People, or Calendar apps, your email, calendar, and contacts will continue to sync properly. You don't need to do anything," reads a support document on syncing Windows 8 and Windows RT with Google's Calendar.

That document was meant to answer questions about Google's December 2012 decision to partially dump Microsoft Exchange ActiveSync (EAS), a popular enterprise-grade synchronization service also widely used by consumers to sync their smartphones and tablets with company email, contacts and calendars.

Google said then that it would drop EAS support for new consumer customers as of Jan. 30, 2013. At the same time, however, it pledged to continue syncing existing free accounts and all paying Google Apps Business, Google Apps Academic and Google Apps Government customers.

According to Google, customers running Google Apps have been able to set up new devices to use Google Sync, which is powered by EAS, after the Jan. 30 deadline.

But Microsoft is not honoring those set-ups, whether previously by consumers or today by Google App for Business users.

"You'll no longer be able to sync your Google calendar with the Calendar app," Microsoft said on the support document in a revision that landed some time between Monday afternoon and today. "Unfortunately, with Google changing the way it supports EAS, your Google calendar can't sync with the Calendar app."

Google was not immediately available to comment or answer questions about whether paying Google Apps customers were still able to set up EAS on their end.

One analyst blamed both sides for the snafu.

"It's disappointing that both Google and Microsoft chose their own interests over end users," said Patrick Moorhead, principal analyst at Moor Insights & Strategy, in an email. "This rift impacts both consumers and businesses negatively and needs to be addressed immediately. Impacted users won't change calendar services [just] to work with Windows 8, so it's up to Microsoft to do the right thing and implement CalDAV. [But] Google deserves ridicule for stopping EAS support, too."

CalDAV (Calendaring Extensions to WebDAV) is a Web standard for accessing online calendars and syncing scheduling information between devices as well as between different software.

Windows 8's Calendar does not support CalDAV. Microsoft declined to comment on whether it will add that functionality to the app.